This Program Project interactively uses organic synthesis, bioanalytical chemistry, structural biology, and[unreadable] molecular biology to elucidate the molecular details by which exogenous and endogenous bifunctional[unreadable] alkylating adducts degrade DNA replication and repair. Efforts will focus on agents in which the two sites of[unreadable] possible nucleophilic attack by the DNA are separated by either two or three carbon atoms. Chlorooxirane, a[unreadable] metabolite of vinyl chloride, is an example of the former and alpha, beta-unsaturated aldehydes, such as acrolein,[unreadable] crotonaldehyde and 4-hydroxynonenal, are examples of the latter. A central hypothesis of this Program[unreadable] Project is that bis-electrophiles can form inter- and intrastrand DNA crosslinks and such crosslinks contribute[unreadable] significantly in the biology of the adducts.[unreadable] Project 1 will develop synthetic routes to the various types of adducts that can be formed by these[unreadable] electrophiles and strategies for their site-specific incorporation into DNA with defined regiochemistry and[unreadable] stereochemistry. The proposed studies are designed to address hypotheses concerning the following: 1) the[unreadable] characterization of intrastrand enal crosslinks and the processing of the intrastrand crosslinks by lesion[unreadable] bypass polymerases; 2) the synthesis and study of N1-dA and N3-dC adducts of Chlorooxirane and acrolein[unreadable] and their deamination products; 3) identification of DNA crosslinks of enals from biological samples and 4)[unreadable] the synthesis and characterization of FAPgamma lesions that are derived from hydrolysis of N7-dG adducts.[unreadable] The DNA adducts to be studied are derived from widely dispersed environmental pollutants or produced[unreadable] endogenously through lipid peroxidation. Given the wide exposure to these compounds, our studies will[unreadable] have direct applications to human health concerns.